1 /*
2 * arch/arm/mach-u300/spi.c
3 *
4 * Copyright (C) 2009 ST-Ericsson AB
5 * License terms: GNU General Public License (GPL) version 2
6 *
7 * Author: Linus Walleij <linus.walleij@stericsson.com>
8 */
9 #include <linux/device.h>
10 #include <linux/amba/bus.h>
11 #include <linux/spi/spi.h>
12 #include <linux/amba/pl022.h>
13 #include <linux/err.h>
14 #include <mach/coh901318.h>
15 #include <mach/dma_channels.h>
16
17 /*
18 * The following is for the actual devices on the SSP/SPI bus
19 */
20 #ifdef CONFIG_MACH_U300_SPIDUMMY
select_dummy_chip(u32 chipselect)21 static void select_dummy_chip(u32 chipselect)
22 {
23 pr_debug("CORE: %s called with CS=0x%x (%s)\n",
24 __func__,
25 chipselect,
26 chipselect ? "unselect chip" : "select chip");
27 /*
28 * Here you would write the chip select value to the GPIO pins if
29 * this was a real chip (but this is a loopback dummy).
30 */
31 }
32
33 struct pl022_config_chip dummy_chip_info = {
34 /* available POLLING_TRANSFER, INTERRUPT_TRANSFER, DMA_TRANSFER */
35 .com_mode = DMA_TRANSFER,
36 .iface = SSP_INTERFACE_MOTOROLA_SPI,
37 /* We can only act as master but SSP_SLAVE is possible in theory */
38 .hierarchy = SSP_MASTER,
39 /* 0 = drive TX even as slave, 1 = do not drive TX as slave */
40 .slave_tx_disable = 0,
41 .rx_lev_trig = SSP_RX_4_OR_MORE_ELEM,
42 .tx_lev_trig = SSP_TX_4_OR_MORE_EMPTY_LOC,
43 .ctrl_len = SSP_BITS_12,
44 .wait_state = SSP_MWIRE_WAIT_ZERO,
45 .duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
46 /*
47 * This is where you insert a call to a function to enable CS
48 * (usually GPIO) for a certain chip.
49 */
50 .cs_control = select_dummy_chip,
51 };
52 #endif
53
54 static struct spi_board_info u300_spi_devices[] = {
55 #ifdef CONFIG_MACH_U300_SPIDUMMY
56 {
57 /* A dummy chip used for loopback tests */
58 .modalias = "spi-dummy",
59 /* Really dummy, pass in additional chip config here */
60 .platform_data = NULL,
61 /* This defines how the controller shall handle the device */
62 .controller_data = &dummy_chip_info,
63 /* .irq - no external IRQ routed from this device */
64 .max_speed_hz = 1000000,
65 .bus_num = 0, /* Only one bus on this chip */
66 .chip_select = 0,
67 /* Means SPI_CS_HIGH, change if e.g low CS */
68 .mode = SPI_MODE_1 | SPI_LOOP,
69 },
70 #endif
71 };
72
73 static struct pl022_ssp_controller ssp_platform_data = {
74 /* If you have several SPI buses this varies, we have only bus 0 */
75 .bus_id = 0,
76 /*
77 * On the APP CPU GPIO 4, 5 and 6 are connected as generic
78 * chip selects for SPI. (Same on U330, U335 and U365.)
79 * TODO: make sure the GPIO driver can select these properly
80 * and do padmuxing accordingly too.
81 */
82 .num_chipselect = 3,
83 #ifdef CONFIG_COH901318
84 .enable_dma = 1,
85 .dma_filter = coh901318_filter_id,
86 .dma_rx_param = (void *) U300_DMA_SPI_RX,
87 .dma_tx_param = (void *) U300_DMA_SPI_TX,
88 #else
89 .enable_dma = 0,
90 #endif
91 };
92
93
u300_spi_init(struct amba_device * adev)94 void __init u300_spi_init(struct amba_device *adev)
95 {
96 adev->dev.platform_data = &ssp_platform_data;
97 }
98
u300_spi_register_board_devices(void)99 void __init u300_spi_register_board_devices(void)
100 {
101 /* Register any SPI devices */
102 spi_register_board_info(u300_spi_devices, ARRAY_SIZE(u300_spi_devices));
103 }
104